The invention relates generally to battery packs for electric vehicles and industrial applications, and more specifically to improvements in intelligent battery packs for simplifying manufacturing and detection of battery pack condition during operation.
Commercial grade high performance battery packs are commonly assembled from individual cells packaged into modules. There is typically some type of on-board intelligence incorporated into individual modules to monitor and control particular operational characteristics of each module, and collectively of the battery pack. This intelligence may be quite rudimentary, or quite sophisticated, based upon needs. Depending upon battery chemistry and application among other factors, various data are gathered by a battery monitoring system.
For enhancing safety and performance, it is preferred that monitoring be performed in real-time. Important information is collected by the on-board intelligence and gathered by the battery monitoring system from the individual modules. The individual modules are uniquely identified and addressed during the monitoring process.
Current manufacturing of battery packs includes serial interconnection of the several modules making up the particular battery pack. There are advantages in manufacturing and maintenance in knowing the geographic location of a particular module in the battery pack. In some applications, the individual modules are distributed throughout the device and it is even more advantageous to know which particular module is which and where it is physically located.
There are many prior art systems for uniquely identifying and addressing specific devices like the modules. Some of these systems include unique codes incorporated into a module during manufacturing, other systems provide for DIP switches, jumpers, or other mechanical solution to set a desired address. There are prior art systems that use electrical systems to gate communication to a next device in a daisy-chain until that device is identified. These have downsides, particularly, a) they require daisy chain interface rather than a bussed interface, and b) they require additional circuitry to gate the communication signals to the next device, which may not be compatible with all communication interfaces due to impedance, voltage range, isolation requirements, and the like.
Such systems burden the manufacturing process with requirements for ensuring unique IDs, as well as mapping the IDs into the geographic chain of the final assembly. Errors in the manufacturing are possible and create difficulties in locating and correcting operational problems indicated by the on-board intelligence. It can be difficult, if at all possible, to disambiguate modules in the event that non-unique IDs have been used. Locating and servicing a module from among many modules, modules that may be distributed geographically, that has been improperly mapped in the geographic string may unduly negatively impact the quality and efficiency of the servicing process.
What is needed is a module enumeration system that does not unduly burden manufacturing or restrict electrical and module interconnect design due to drawbacks with existing designs as discussed above.